Coronaviruses are a family of RNA viruses that infect avians and mammals, including humans and swine. Coronaviruses belong to the family Coronaviridae, which has four main sub-groupings, known as alphacoronavirus, betacoronavirus, gammacoronavirus and deltacoronavirus. Human coronaviruses include alphacoronaviruses 229E and NL63, and betacoronaviruses OC43, HKU1, SARS-CoV (the coronavirus that causes severe acute respiratory syndrome, or SARS), and MERS-CoV (the coronavirus that causes Middle East Respiratory Syndrome, or MERS). Porcine coronaviruses include alphacoronaviruses, such as transmissible gastroenteritis virus, porcine respiratory coronavirus, and porcine epidemic diarrhea virus (PEDV); betacoronaviruses, such as porcine hemagglutinating encephalomyelitis virus; and deltacoronavirus, such as porcine deltacoronavirus (PDCoV). Other coronaviruses include, but are not limited to, bovine coronavirus (BCV), feline coronavirus (FCoV), canine coronavirus (CCoV), avian infectious bronchitis virus (IBV), and turkey coronavirus (TCV). Porcine coronaviruses are important diseases in swine production. For example, PEDV is a highly infectious coronavirus that infects the intestinal system of a pig, typically causing diarrhea and dehydration. While adult pigs mostly become sick and lose weight after becoming infected, the virus is often fatal to newborn piglets. Infected herds can suffer a loss of from 50% to 100% of the piglets for a four to five week period. It has been estimated that between June 2013 and March 2014 over 4 million piglets were lost to PEDV in USA.